Ask the MAC – 15 Jan 2026

Rules of the road…

Q) A driver works under domestic hours for his working week.

For one day of that working week he is required to do a route that falls under assimilated rules.

Does that mean their whole working week falls under assimilated rules, or is it a rolling 24-hour day that determines what rules he/she fall under?

A) This would be classed as ‘mixed driving’. On days where a driver is subject to the assimilated rules only, the assimilated rules must be followed on those days and the driver must also comply with the weekly rest and driving limits for that fixed week.

On days where the driver is only subject to the domestic rules, only the domestic rules apply, unless an assimilated weekly rest is required to commence on that day.

On days where drivers will be subject to both assimilated and domestic rules (say where a 3.5t vehicle draws a trailer for part of the day in scope of assimilated rules), the following should be noted:

• Both sets of rules must be met for the day. Pay particular attention to the 11 hour domestic duty limit and the daily rest requirements under assimilated rules.

• For domestic rules calculations, driving under assimilated rules counts as driving.

• Other work under assimilated rules counts as duty time.

• Rest and breaks under assimilated rules do not count as duty.

• For assimilated rules calculations, both driving and duty time under domestic rules count as other work.

• When driving under assimilated rules, drivers must remember to take breaks from driving.

Tacho trouble…

Q) We have got a tacho calibration centre that does not and will not sign the certificate after calibration, and they will only provide the tester’s name.

Every other centre we use complete the testers name and sign a physical signature.

I have been through the approved tachograph centre manual which manages to avoid the subject quite nicely.

MOT and LOLER certificates are signed, so in my mind, so should these.

Can you please put my mind at rest?

There was an approved tachograph centre special notice that was issued in 2020, which states the following:

‘Newer tachograph calibration software can complete the technician details on the calibration certificate.

Regardless of this, when the vehicle is calibrated it is still necessary for the documents to be signed by the technician. This includes any kept for approved tachograph centre records.

If a copy is requested by the operator, then the certificate may be endorsed with ‘Copy’ or ‘Duplicate’ and no signature is required. Alternatively, a photocopy of the signed record can be used, endorsed as ‘Copy’ or ‘Duplicate’.